1. Field of the Invention
The invention relates to the field of monitoring and control of audiovisual communications equipment and in particular to a system for determining the electronic media viewing and listening by an user. For example, the invention relates generally to a two-way digital data communication system which performs audience viewing and listening determination from electronic media such as cable and broadcast television, AM and FM, video magnetic tape and optical video disk.
2. Description of the Prior Art
Television and radio audience monitoring or rating has for the most part been accomplished by using viewer or listener written diaries in which the selected television channel or radio station, program name and corresponding times are manually entered by the cooperating viewers or listeners. The manual diary method is subject to errors which are usually due to the entry of incorrect information or the failure of entry altogether. Furthermore, manual entry provides output information longer after the program has been transmitted, which information can be compiled and analyzed only at great expense and effort. Furthermore, manual logs typically ignore the use of video magnetic tapes or optical video disks recording or play back as part of the viewer behavior.
The prior art has developed some limited audience determination systems. In the most common of these prior art systems, an electronic diary is kept where the user enters an identification number, and a channel or a station number via a keyboard. These data is transmitted over telephone lines to a central computer. Such a system is illustrated, for example, in CHEUNG, "Television Audience Measuring System", U.S. Pat. No. 4,258,386 (1981). This method is similarly error prone because the viewer has to remember and correctly enter an identification number. Furthermore, the system does not track the number of people entering or leaving the viewer area, ignores the operation of video magnetic tape or optical disk recording or play back, provides analyzed information only long after the programs are transmitted, and has only a one way data transmission link.
Another prior art method is based on a video magnetic tape recorder which records exactly what the viewer selects and watches. However, in this method the circuit of the television set must be modified so that the selected channel can be monitored and recorded. Furthermore, this method does not remove the limitations inherent in an electronic diary, namely that the number of people entering or leaving the viewing area is not tracked, operation of video magnetic or optical disk recording or playback is ignored and analyzed information is provided only long after the programs are transmitted. See for example, WATANABE, "Television Audience Measurement System," U.S. Pat. No. 3,803,349 (1974).
A third methodology requires a modification of a television circuit to allow monitoring of the local oscillator radio frequency voltage in the television tuner so that the selected channel can be identified. This voltage is transmitted via telephone lines to a central computer and again has all the limitations of an electronic diary. See CHEUNG, "Television Audience Measuring System," U.S. Pat. No. 4,258,386 (1981).
Other systems have been devised which allow interrogation of a selected group of television sets from a central station, as might for example, be found in a closed circuit system within a hotel. See SULLIVAN, "Interrogated System," U.S. Pat. No. 3878,322 (1975); and SULLIVAN, "Interrogated Transponder System," U.S. Pat. No. 4,079,414 (1978). However, in many of these cases, the transmitted television signal must be especially encoded and the circuitry of the television receivers must incorporate unique logic and transponding circuitry capable of interpreting and responding to the uniquely encoded transmitted television signal.
Similarly, the prior art has devised a system wherein broadcast television may be monitored on a number of specially modified television systems by a select audience in viewing rooms with means for providing an audience reaction to the broadcast program. See for example, FROHBACH, "Television Audience Survey System Providing Feedback Of Accumulative Survey Results To Individual Television Viewer," U.S. Pat. No. 4,107,735 (1978). However, such system again require modification of a television circuit and are not practical for widespread usage in the viewer's own office or residence.
Finally, the prior art has devised a number of systems which can be employed in cable television networks to allow two-way data communication between the viewers and a central station. However, many of these two-way data communication systems do not provide any non-intrusive monitoring of television viewing, but simply use the television as part of an audiovisual receiving station in combination with a keyboard or other input device which allows the viewer to respond to a central station. With the viewer chooses not to respond, there is no way in which the viewing behavior can be monitored. See TABATA, "Line Monitoring Device In Two-Way Data Communication System," U.S. Pat. No. 4,365,259 (1982).
In those cases where programs selection can actually be monitored, the central station is capable of sensing the viewed channel only by being hardwired to the tuning mechanism of the television receiver or to the channel selection keyboard and circuitry. See RICKETTS et al., "Premium Interactive Communication System," U.S. Pat. No. 3,997,718, and MATSUMOTO et al., "Interactive CATV System," U.S. Pat. No. 4,245,245 (1981).